1. Field of the Invention
The present invention relates to a chip components feeding apparatus that aligns chip component, which have a predetermined shape and are put in a bulk state, in a predetermined orientation and conveys the chip component after alignment to a predetermined take-out position, and more particular, to a chip components feeding apparatus using a tube as means for conveyance of the chip component after alignment to a take-out position, and making use of an air flow based on an action of negative pressure, as power for conveyance.
2. Description of Related Art
JP-A-2004-200491 filed by the applicant of the present application is known to disclose a chip components feeding apparatus using a tube as means for conveyance of chip component after alignment to a take-out position, and making use of an air flow based on an action of negative pressure, as power for conveyance.
The chip components feeding apparatus disclosed in the JP-A-2004-200491 comprises a chip component alignment unit functioning to align chip component, which have a predetermined shape and are put in a bulk state, in a predetermined orientation to discharge the same from an outlet, and a chip component take-out unit functioning to stop the chip component supplied to an internal chip component passage in an aligned state to expose a leading part outside through a chip component take-out outlet, the outlet of the chip component alignment unit being connected to a rear end of the chip component passage of the chip component take-out unit by means of a chip component conveyance tube. Provided in the chip component take-out unit is an air intake path to apply negative pressure in the chip component conveyance tube through the internal chip component passage, an end of the air intake path being connected to an air cylinder as a negative pressure generation source.
In case of making use of an air flow based on an action of negative pressure, as power for conveyance, a phenomenon occurs, in which an interior of a conveyance passage including a chip component conveyance tube is not returned to atmospheric pressure and succeeding chip components are put in a state of pushing preceding chip components even when the action of negative pressure is released. Such phenomenon is also called residual pressure phenomenon and liable to occur as a passage shape of a chip component conveyance tube and a size of chip component become small.
When such residual pressure phenomenon occurs, succeeding chip component apply a push load on a leading part and the leading part is put in a state of being interposed between a chip component stoppage portion and a second chip component, so that a taking-out miss is generated when a suction nozzle is used to take out a leading part from a chip component take-out outlet.
In order to dissolve interposition of a leading part due to the residual pressure phenomenon, there are tested a method of displacing a chip component stoppage portion slightly forward when a leading part is to be taken out, and a method of holding succeeding chip component so as to make the same immovable, in combination with the former method, but it cannot be said that the former method is sufficient to dissolve interposition since even when the chip component stoppage portion is displaced forward, succeeding chip component advance further than such displacement. Of course, interposition can be dissolved when such displacement is considerably increased, but such design cannot be practically adopted since a chip component taking-out position (a position of a leading part) is varied greatly. Also, the latter method cannot be said to be sufficient to dissolve interposition since succeeding chip component advance against a holding force.